Governor for air-motors.



M. CLARK.

GOVERNOR FOR AIR MOTORS.

APPLICATION FILED SEPT. 12. I917.

. Patented Mar. 25,1919.

LIYNO. wAsNlnamN, n, c.

UNITED STATES PATENT OFFICE.

MELVILLE CLARK, OF CHICAGO, ILLINOIS, ASSIGNOR TO MELVILLE CLARK PIANO COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

covmmoza FOR AIR-MOTORS.

Specification of Letters Patent.

Patented Mar. 25, 1919.

Application filed September 12, 1917. Serial No. 190,903.

To all whom it may concern:

Be it known that I, MELVILLE CLARK, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Governors for Air-Motors, of which the following is a specification, refer ence being had to the accompanying drawings, forming a part thereof. I

The purpose of this invention is to provide an improved governor for an air motor particularly designed for such motors when employed for actuating the note-sheet driving mechanism of an automatic piano player. It consists in the elements and features of construction shown and described as indi cated by the claims.

In the drawings Figure 1 is a plan view showing a portion of an air motor equipped with the governing devices embodying this invention.

Fig. 2 is a front elevation with the front plate of the valve chamber removed.

Fig. 3 is a section at the line 33 on Fig. 2.

Fig.4 is a section at the line H on Fig. 3, extending through the exhaust controlling valve box only.

In the structure shown in the drawings, A is a conventional representation of an air motor of familiar form; B represents c0nventionally the exhaust devices for operating the air. motor, and C is' an air pipe connection of the exhaust devices to the motor, connection being made by way of the governing devices hereinafter explained. 1 1s a chamber with which the pipe, G, is connected through the block, 2, mounted on said chamber. 3 is a chamber partitioned from the chamber, 1, by the partition, 4, which has a port, 5, controlled by the valve, 6, which is the usual tempo valve havin its stem ex tending out through the end of the chamber and connected with an actuator, 7, which is in turn connected with the tempo lever, 8, which moves over a graduated scale, 9, for regulating and indicating the speed of playing. The chamber, 3, is connected with the motor by a pipe, O said connection of the pipe, G with the chamber, 3, being made through the block, 2. Besides the communication which the chamber, 1, has with the chamber, 2, by way of the valved port, 5, it has a second communication through the partition, e, by means of a narrow slit forming a port, 5*, which is controlled by a valve, 10, sliding in said partition in said chamber, 3, and having its stem, 10 extending out through the opposite end of said chamber from that through which the stem of the valve, 6, extends. Said stem, 10 is connected outside said member with the moving wall, 11, of the pneumatic, 11, mounted on the end of the chamber and connected by the tube, 12, with the exhaust devices.

The construction thus far described comprises beside what may be termed the direct connection between the exhaust devices and the motor consisting of the chambers, 1 and 3, communicating through the port, 5, controlled by the valve, 6, a second connection which may be called a by-pass, consisting of the communication between the chambers, 1 and 3, which is controlled by the valve, 10. The first mentioned or main connection is directly regulated by the tempo lever operating the valve, 6, in accordance with the speed of playing desired. But with any given adjustment of the tempo valve, uncovering the port, 5, to any given extent, the speed of operation of the motor and subsequent speed of playing will vary with the degree of exhaust tension existing in the exhaust devices and operating through the connection controlled by the tempo valve upon the motor. In the absence of means to prevent such results, this would result in a speed of operation of the motor and consequent speed of playing, varying with the varying exhaust tension produced by the exhaust devices which as is well understood, is varied by the pumping according to the loudness of playing desired. To prevent variation of the speed accompanying the variation of loudness, the by-pass'controlling valve, 10, is operated by the pneumatic, 11, connected with the exhaust devices, so as to be collapsed more or less according as'the exhaust tension is more or less, and by its collapse to close the valve, 10, more or less. The motor is thus operated by two distinct quantities, so to speak, of exhaust, one of which, that controlled by the valve 10, is diminished as the exhaust tension increases, while the other is subject to the control of the tempo lever. By properly proportioning the areas of the two ports controlled by the two valves, 6 and 10, respectively, the speed of the motor for any given adjustment of the tempo valve 6, may be rendered measurably constant throughout considerable variations of the exhaust tension.

For more completely eificient" regulation,

however, an" additional expedient is employed, consisting in governingthe communication of the exhaust with the pneumatiq-j '11, in relation to the adjustment of the tempo lever andvalve, 6'; This is efi'ectedby providing a valve control'intthe passage which"vv connects the pneumatic, 11, with the exhaust devicesyandfor this purpose there is 17 whichis controlled by a sliding valve,

18, in:the chamber, 16", said valve havingits stem, 18?, extending out throughthe end of the chamber for direct operation by the tempo valve slide bar by means- 0f a: rigid cross connection, 20. When the tempo lever V is-operated for-opening'the tempo valve, at

the port, 1

a'wcertain pointi-n its operation,-'that is, Whenit ihas reached adjustment for a certain' speed, the further movement of: the tempo-valve indirection for opening to in crease the s eedi moves the valve, 18, over 7 uncovering the same .to' a greater for less extent 1 according to the con- 7 tinued movement in the opening direction of the tempo-valve, and therebyincreases the communication of the exhaust devices s with j the pneumatic, l1,:and the 'degreeof collapse of said pneumatic which will be 7 produced" by any r given said tension' then existing in the exhaust devices, Such collapse operates, as already explained, to close the valve, 10, diminishing the communication of theexhaust deviceswith the motor.

The several devices described cooperating, give theresult; that, at any adjustment of the tempo valve, thecommu-nication of the exhaust devices with the motor'is diminished as the exhaust tension increases,- and that the eiiect of the exhaust tension to thus del V crease the communicationiwith themotor is increased as the tempo'ivalve is, opened exhaust devices by which it is operated,,. air' connections from the exhaust devices to the .motor 'comprising aimain passage, a by-pass,

a valve in the main passage and tempo controlling devices for operating that valve; a

pneumatically operated valve in the by-pass' having air connections from the exhaustdevices for operating said pne'uma'tically- 1 operated valve in one direction and yielding means resi-sting'its actuation in that'direction,'a nd means controlled by the tempocontrollin'gdevices for controlling said last mentioned airconnection with the exhaust devices. r v V 2." Incomb'ination with an air motor and exhaust devices-by whichitis operated, air

connections from the exhaust devices, to

the 'motor comprising a main passage and byp ass, a valvein themain passage and tempo-controlling devices for operating that valve, a pneumatically-actuatedvalve in the by-pass connection; air connections from the exhaust devices for actuating said last'mentionedvalve independent 'of'the valve control in the air connection from the exhaust devices 'to themotor;

3. In a structure such as defined in claim l,'the-means"of controllingthe exhaust'c0n nection with the pneumatic valve-actuating devices, comprising a partitioned chamber in'the air conduit which connects sai d'pneumatic devices with theexhaust devices, the partition havinga narrow and elongated slot; a valve mountedfor sliding longitudL- nally over said slot,having mechanical operatingconnectionsfromthe tempo valve oper{ ating means to said slot controlling valve.

In testimony whereof, I have hereunto setthis 7th day my hand at Chicago, Illinois, of September, 1917.

' V MELVILLE CLARK.

. Copies ofthis rpatent lnaybeobtaiued forvfivecents each, by addressing the. Commissionerbf Patents;

Washington; 1L0. 

